Hays County, Texas
7 ZIP codes · Avg score 80/100 · Grade B · Updated 2026-06-03
Compared to state averages, Hays County scores well — its 7 ZIP codes sit above the baseline for tap water quality.
How Hays County Compares
How Hays County Compares
Hays County scores 2 points below the Texas state average (82/100) and 12 points above the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Hays County, Texas
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 10.8 (asthma 9.3%, diabetes 10.1%)
Estimated additional annual cost per homeowner: $1,876, driven primarily by flood
Infrastructure: 0.216% avg pipe failure probability
20% of homes built before 1978 (lead paint era)
Violation History (2022–2025)
↑ Worsening trendEPA violation counts by year across Hays County water systems. Health-based shown in red, total in blue.
Peak year: 2024 with 16 violations. Past 5 years: 44 total (44 health-based). Health-based violations are rising versus the prior 2-year window — worth closer monitoring.
Source: EPA SDWIS historical violations. Data may lag 6–12 months for the most recent year.
County Health Indicators vs National Average
Black markers indicate national averages. Source: CDC PLACES, Census ACS.
Infrastructure Overview
Sources: Census ACS (housing age), EPA SDWIS (infrastructure risk model), state bridge inspection data.
Compound Risk Breakdown
Estimated additional annual cost per homeowner: $1,876
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
90,896 housing units in Hays County
Source: U.S. Census Bureau ACS B25034 (Year Structure Built).
Water Safety Affordability
How much it costs to fix water issues relative to home values in Hays County
Remediation costs are relatively manageable for most homeowners in Hays County, representing a small fraction of property value.
Remediation includes water filtration, lead abatement, radon mitigation, and flood protection where applicable. Source: Census ACS, EPA SDWIS.
Health Outcomes vs National Average
CDC PLACES data for Hays County residents
Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.
Water Systems with Most Violations
Top 5 systems in Hays County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | La Ventana Water Supply System | 747 | 18 |
| 2 | Dripping Springs Water Supply Corporation | 8,037 | 17 |
| 3 | City of Kyle | 52,000 | 15 |
| 4 | CITY OF SAN MARCOS | 72,970 | 13 |
| 5 | Wimberley Water Supply Corporation | 5,334 | 12 |
32 total water systems serve Hays County.
All ZIP Codes in Hays County
7 ZIP codes tracked in Hays County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 78640 | Kyle | 90 | A | 0 | $291K |
| 2 | 78620 | Dripping Springs | 89 | A | 6 (1 health) | $625K |
| 3 | 78667 | San Marcos | 85 | A | 1 | — |
| 4 | 78610 | Buda | 84 | B | 3 | $379K |
| 5 | 78666 | San Marcos | 80 | B | 1 | $272K |
| 6 | 78676 | Wimberley | 69 | C | 11 (1 health) | $476K |
| 7 | 78674 | Weir | 66 | C | 0 | $43K |
Recommended Buyer Guides for Hays County
Where county records show a lead exceedance or pre-1978 housing concentration, lead-specific filters and test kits move toward the top of the list.
- Best Sump Pumps — Flood is the top compound risk factor
- Best Mold Test Kits — Flood-driven moisture and mold risk
Deep Dive Reports
Detailed analysis for Hays County, Texas
Overview
Hays County in Texas covers 7 ZIP codes with an average Home Safety Score of B (80/100).
5 of 7 ZIP codes have recorded EPA violations. 2 health-based violations have been documented.
← Back to Texas water quality report
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Home values: U.S. Census Bureau ACS (median estimates by ZCTA)
Updated daily.